Radio, PC Technology Join Forces : High tech: Wireless computer networks are evolving that will revolutionize data transmission, but not without some hitches.
It’s a marriage made in technology heaven, an inevitable match-up of two of the most powerful tools in modern electronics: portable personal computers and advanced radio communications.
Need to send an electronic message, or search a database, or retrieve a file while you’re sitting in an airport departure lounge? Soon you’ll simply take a little computer out of your pocket, and with a few taps on a miniature keyboard or even the stroke of a pen, you’ll be logged in.
Though some types of wireless computer networks have been in place for years, a flurry of recent developments promise to dramatically expand the scope of the technology. Several companies are now pouring hundreds of millions of dollars into computer communications networks that will work hand-in-hand with a new generation of tiny, lightweight computer devices.
Like many marriages, though, the joining of computers and radio communications is complicated and conflict-ridden. The various networks are not compatible with one another, and it will be impossible to equip computers to work with all of them. Further advances are still needed to make the communications devices smaller and cheaper. And potential customers will have to develop new software if they are to make mobile computer communications a valuable addition to their operations, rather than just a fun gimmick.
“Customers don’t buy technology; they buy things that make their lives easier,” says Jack W. Blumenstein, president of the Ardis data network, a joint venture of Motorola and International Business Machines.
“As an industry, our biggest challenge is understanding what it takes for the customer to make wireless communications simple and painless.”
For certain industries, mobile data networks are not a new concept at all. Ardis, for example, was formed in 1984 as a private data network for IBM field service technicians. Express delivery firms, taxi cab companies and public safety organizations--to name just a few--have long had private radio networks that use specialized terminals to carry message traffic between the field and the home office.
Paging services have also provided data communications for a variety of businesses, though paging is a one-way service and is often limited to very short messages. Some ambitious cellular telephone users have already equipped their phones with cellular modems, allowing them to send and receive computer data.
Over the past year, however, Ardis and Ram Mobile Data--which has financial backing from BellSouth and uses technology from the Swedish telecommunications giant Ericsson--have been moving aggressively to build nationwide, general-purpose computer messaging services. Cellular phone operators are experimenting with a variety of methods for making their networks more useful for data communications. Cellular operator McCaw Communications, for example, recently announced that it is working with computer software vendor Oracle Corp. to develop a broadcast data service.
At the same time, the rapid development of notebook personal computers, “palmtop” PCs such as the 11-ounce HP 95 from Hewlett-Packard, and pen-based PCs that use a stylus instead of a keyboard promises to create a broad new base of machines that could benefit from wireless communications.
Apple Computer Chairman John Sculley regularly cites portability and communications as important new opportunities for his company, and an Apple spin-off called General Magic--which also has equity funding from Sony and possibly other big electronics firms--is developing a “personal communicator” that will incorporate wireless technology.
“It’s an enormously exciting area,” says Richard Shaffer, principal of Technologic Partners in New York. For pen-based computers in particular, he says, wireless communications is “a major enabling technology” that could become the most important component of future pen machines.
Potential users of wireless networks, though, will have some tricky choices to make. Both the Ardis and the Ram Mobile Data networks are designed to handle data in short bursts, or “packets.” The packets, which carry their own address information, are transmitted by radio from the PC to the data network base station. From there, they travel through a traditional, wired communications network and land either at a “host” computer that’s connected to the network or at another radio base station for transmission to another mobile computer.
Packet networks are very efficient for sending short messages; each packet takes up very little room on the radio channel, and because the packets carry their own address, they can be sent off to the network for routing without the delay associated with placing a telephone call. Ardis and Ram allow users to send a message in seconds and charge only a few cents for each message.
The disadvantage of packet networks, though, is that they aren’t good for sending more than a few dozen words at a time. For transmitting or receiving long files, so-called circuit-switched networks--which establish a full end-to-end communications link--are far superior.
Traditional voice telephone networks use circuit switching, and so do cellular networks. Thus cellular phone systems--both the existing ones and global, satellite-based systems that are now being developed by Motorola and other companies--are likely to emerge as the preferred choice for some mobile data applications.
The current cellular systems, however, don’t carry data traffic very well, especially not in a moving vehicle. Thus cellular carriers are looking forward to the deployment of the next generation of cellular technology, which will use a digital computer code to carry voice and data traffic alike, and thus will be far more efficient for data communications.
In the meantime, though, some of them--including Pactel Cellular--are developing technical fixes that will improve the data handling capabilities of the existing networks. And Pactel Cellular President Susan Swenson says the company is also planning to deploy a packet network of its own to compete with Ardis and Ram.
Swenson emphasizes the importance of developing standards for mobile data so that any properly equipped computer would be able to use any network, but there is now little movement in that direction. For the foreseeable future, indeed, computer buyers will have to decide what kind of service they want to use and then buy the modem that matches.
They’ll need one type of device for packet data, another for cellular phone systems and a third for another type of system that’s expected to gain popularity soon: wireless local area networks, which allow portable PCs being used within a building, or on a campus, to link up to PC networks and exchange large amounts of information.
To further complicate matters, paging companies are rapidly developing new one-way data services. Rather than simply receiving a beep or a phone number and a short message on a pager, customers will be able to get stock quotes or sports scores or other information sent directly to a pager-equipped PC. Motorola’s paging subsidiary is already offering such a service along with a special receiving device that plugs directly into the HP 95 miniature computer.
For many applications involving large corporate customers, the looming incompatibilities won’t be a big problem. In equipping a fleet of trucks with mobile data systems, for example, companies are likely in any case to develop a customized system that’s integrated with their existing computer operations. And corporate systems of this sort are likely to be the biggest users of mobile data in the early stages.
In the future, though, as wireless communication is used for more routine tasks, compatibility will be a more serious problem. Ideally, the future “personal communicator” will be able to “talk” to a local area network when it is in a building, or send messages over a packet data network, or retrieve files via a circuit-switched telephone line. Only then will the marriage of portable computing and radio communications have truly been consummated.
